Clock



FIG. 1 is a front elevational view of a clock showing my new design, the rear view being plain and unornamented;

FIG. 2 is a right side elevational view thereof, the left side being substantially a mirror image thereof;

FIG. 3 is a top plan view thereof; and

FIG. 4 is a top and right, front perspective view thereof. 

The ornamental design for a clock, shown. 